In a cellular system voice, data, and signaling traffic is sent between mobile devices and a base station located at a cell tower site. The voice, data, and signaling traffic is backhauled from the base station at the cell tower site to a base station controller and a mobile switching center.
Various communication standards can be used to send the signals from the mobile devices to the base station. One exemplary communication standard is code division multiple access (CDMA). CDMA is a form of multiplexing that does not divide up the channel by time (as in TDMA), or frequency (as in FDMA), but instead encodes data with a special code associated with each channel.